Predictors of cardiac involvement in myotonic dystrophy type 1: a retrospective study
A S Fernandes, M Moreira, J Marques, R FloresAbstract
Introduction
Myotonic dystrophy type 1 (DM1) is a genetic, inherited, multisystem disease in which cardiac involvement (CI) is a major cause of morbidity and mortality. Early identification of markers is essential for a preventive and personalized approach.
Objectives
To identify clinical, electrocardiographic, and imaging predictors of cardiac involvement in patients with DM1.
Methods
We conducted a single-center, retrospective, observational study including 38 adults with DM1 followed at the Cardiology Department of between 2010 and 2025. Clinical, electrocardiographic, and imaging characteristics at the time of diagnosis were assessed. Their association with future CI and their ability to discriminate it were analyzed using univariable and multivariable logistic regression and ROC curves.
Results
Mean age was 52.32 years, with diagnosis at 40.68 years. Age showed moderate overall performance in predicting CI (AUC = 0.704; p = 0.064). The presence of electrocardiogram (ECG) abnormalities at diagnosis demonstrated high discriminative ability (AUC = 0.804; p < 0.001). The PR interval was significantly associated with CI in univariable analysis (OR = 1.03; p = 0.045), showed the same trend in multivariable analysis (aOR = 1.02; p = 0.062), and retained predictive value on the ROC curve (AUC = 0.734; p = 0.008). The PR interval was also a predictor of advanced atrioventricular (AV) conduction abnormalities (AUC = 0.779; p = 0.005). Global longitudinal strain (GLS) was marginally associated with left ventricular dysfunction (OR = 1,87; p = 0,064) but showed excellent performance on ROC analysis (AUC = 0.806; p = 0.013).
Conclusions
PR-interval prolongation and ECG abnormalities at diagnosis enabled early identification of patients at risk of developing CI. GLS may serve as an early marker of left ventricular dysfunction.